The recent move to strip out DSS support from the openssh package
means that older key formats cause the key-printing command to
fail. Rather than causing the entire unit to fail, we should instead
skip those keys - while still letting the error through to the
console - and continue to print other keys the loop may find.
This also removes automatic enablement/mounting of instance store swap
devices and ext3 filesystems. This behaviour is strongly opinionated
and shouldn't be enabled by default.
The unionfs behaviour never took effect anyway, because the AMI
manifest path only exists for instance store-backed AMIs, which have
not been supported by nixpkgs since
84742e2293 (2019).
A centralized list for these renames is not good because:
- It breaks disabledModules for modules that have a rename defined
- Adding/removing renames for a module means having to find them in the
central file
- Merge conflicts due to multiple people editing the central file
curl does not retry if it is unable to connect to the metadata server.
For some reason, when creating a new AMI with a recent nixpkgs, the
metadata server would not be available when fetch-ec2-data ran. Switching
to wget that can retry even on TCP connection errors solved this problem.
I also made the fetch-ec2-data depend on ip-up.target, to get it to start
a bit later.
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
